Electric field

Lessons

Electric field (E) is the electric force exerted by a charge Q on another charge q, per unit charge of q. It is a vector quantity.

By convention, the direction of electric field vectors is defined as the direction that a positive test charge would move if placed in the field. Fe points in the same direction as E for positive charges, and in the opposite direction of E for negative charges.

A test charge is a point charge with a very small magnitude. Test charges have a small magnitude charge so that the electric field of the test charge is negligible and does not affect the electric field that is being investigated.